In the field of clinical or biochemical examinations, a colorimetric analysis is employed as a method for analyzing components such as glucose, cholesterol, or the like in a sample. For example, the colorimetric analysis of glucose is generally as follows: a glucose oxidase reacts with glucose (substrate) to generate gluconolactone and hydrogen peroxide; and the hydrogen peroxide is detected by a coloring reagent, such as a Trinder's reagent, in the presence of peroxidase. This method, in which the concentration of a substrate is measured indirectly via hydrogen peroxide, has been limited not only to glucose, but also used for cholesterol or the like.
However, the conventional colorimetric analysis involves the following problems. First, the time required for measurement is long because an analyte is not measured directly, but indirectly via hydrogen peroxide. For example, it takes 30 to 60 seconds to measure glucose. Second, it is difficult to set conditions because two different enzyme reaction systems should be stabilized simultaneously. Finally, the conventional calorimetric analysis requires oxygen, and poor oxygen may lead to an insufficient reaction.